When D'Angelo finally sang his first notes on stage at the Filadelfia church in Stockholm last week, you could almost hear the audience breathe a mass sigh of relief. Like most fans, the Swedish crowd had been patiently waiting for over a decade to hear from the Virginia-born R&B singer again. D'Angelo has only released two albums in the course of a career that began in 1995, the last in January 2000, but those final moments before he stepped on stage felt like the longest of all. Could he summon even part of his old magic? What shape would he be in? Would he even turn up?

A few hours earlier, I had sat in the reception of Stockholm's Lydmar hotel, in the vain hope of cornering the 37-year old singer. Rumour had it that the only person granted an interview, a Swedish soul DJ known to the singer's camp, had in the end been turned away because D'Angelo was too nervous. Instead I spoke to music journalist Maja Bredburg, who had seen D'Angelo on tour in 2000, at the time of his first comeback with the multi-award-winning album, Voodoo. Bredburg was sceptical that he could ever match the performance she had witnessed then. In the intervening 12 years, there has been no followup album, and the few interviews that D'Angelo has given have revealed little more than his interest in the Washington DC hardcore band Bad Brains.

When D'Angelo released his first album, Brown Sugar, it was 1995, right in the middle of the golden era of hip-hop and R&B. Mary J Blige, Nas and Wu-Tang Clan all released their debuts in the same period, while a new genre, coined neo soul, emerged with Erykah Badu, Lauryn Hill and D'Angelo at its helm. Brown Sugar's success was both instantaneous and long-lasting, as the record turned platinum in the US.

Born in Richmond, Virginia, to a deeply religious Pentecostal family – he recalled witnessing excorcisms – D'Angelo's musical education began in church. His family says he showed natural vocal ability and a precocious talent for the piano before he was old enough to fully reach the pedals. Much of the material for Brown Sugar was written in his early teens, and there is something almost hymn-like in the structure of songs such as Higher: "With God as my witness and watching over, We'll write our love in the stone, Please give us strength Lord to fight our battles." In combining the traditions of funk and soul with a sense of the devout, D'Angelo created something that sounded fresh and individual.

It was all going so well, but it would be five years until a followup emerged. But that record, Voodoo, hit No 1 in the charts and won two Grammys, and the live tour that followed still has fans rhapsodising. Mark Ronson, who once shared a manager with D'Angelo, says the show in New York that he saw in 2000 was perhaps the best he's ever seen. "It was like Earth, Wind and Fire meets Fela Kuti," he says. "It was more than anyone expected from a soul artist. I didn't stop smiling. I remember leaving the show with a girl I was dating at the time, and she was in a foul mood. I asked what was wrong and she said: 'I've never seen you as happy with me as you were watching him tonight.'"

D'Angelo's looks also had a lot to do with his comeback. If you could point to one moment that continues to define the singer today it is the unforgettable music promo for Untitled (How Does it Feel), in which the camera focuses only on D'Angelo, naked from the waist up, revealing a ripped set of muscles. For the duration of the song (initially conceived as a tribute to Prince), he mumbles and sings with his eyes closed, looking to be in a state of ecstasy. As journalist Christopher John Farley, who interviewed D'Angelo in 2000, told me: "It takes a serious amount of work to look like that. His devotion to his look demonstrated his seriousness about himself, and in a way, his art."

During the eight-month Voodoo tour, those fans who failed to gain D'Angelo's attention by throwing their clothes at him would rush the stage to try to disrobe him. Ahmir "Questlove" Thompson of the Roots, drummer and musical producer of that tour, would later suggest that the attention backfired, leaving D'Angelo feeling like nothing more than a sex object. The tour began to take its toll, as did that well-cultivated physique. "If you create a persona that needs to be tended as carefully as a bonsai tree, it will start to wear you out," says Farley.

D'Angelo had dated fellow soul singer Angie Stone in the 90s, and they had a son, Michael, in 1998. Now rumours of alcoholism began to emerge, and since that tour and until his appearance in Stockholm, the stage would lose sight of D'Angelo.

There have been rumours of a new album, provisionally titled James River, which at one stage was slated to feature contributions from Prince as well as Cee Lo Green and Mark Ronson. But in 2010, the announcement on his MySpace site that a record was imminent was removed. There were occasional collaborations with acts including Common and Snoop Dogg, but the only songs of D'Angelo's that leaked – such as a cover of Soundgarden's Black Hole Sun, earlier this year – failed to convince anyone that a real comeback was in the offing.

In the meantime, D'Angelo's face – now swollen and pudgy – became familiar only from police mugshots. In January 2005, he was arrested and charged with possession of marijuana, possession of a controlled substance, and driving while intoxicated. He pleaded guilty on two counts and later that year received a three-year suspended sentence on the cocaine possession charge. The week following that hearing, he was seriously injured when an SUV he was driving in Richmond hit a fence, ejecting him from the vehicle. As a result, he later received a nine-month suspended jail sentence.

In the interim, his former A&R man Gary Harris had tried to take him to Eric Clapton's Crossroads rehab centre in Antigua. Arriving at D'Angelo's mansion in Virginia, Harris saw the scale of his problems, with empty bottles everywhere. "There was scotch, vodka, beer," Harris later told Spin magazine. "While I was waiting he emptied the contents out of the corners of three or four bottles to get a shot."

In March last year, D'Angelo was also arrested and charged with solicitation after asking a female undercover police officer for oral sex in New York's West Village. He pleaded not guilty.

Meanwhile, there was still no sign of a record, but in October last year Questlove told an interviewer, "He's in the home stretch right now". Contrary to reports, Ronson hasn't been in the studio with D'Angelo, but as he said to me: "When it was reported I was working with him, everyone from the rapper Saigon to Paul Smith from Maxïmo Park got in touch, saying how excited they were. I think it shows how respected and admired he is for a whole cross section of people, not just 'R&B' fans."

Then came the announcement of a string of live dates, beginning out of the spotlight, in Sweden, where D'Angelo has always counted a number of his keenest fans. Travelling there may have been an act of faith, but on a snowy January night in a small church, D'Angelo made two things clear. For one, he's in shape. Older, less svelte than in his famous video, but healthy and full of vim. For two, the man can still sing, and is more than a match for his peers or any young pretender. New material was thin on the ground The suggestion from his label was that the D-tour, as its being called, was an exercise in inspiration, not an introduction to album No 3. But suddenly, as he bantered with the audience before launching into prolonged, funkier versions of the likes of Brown Sugar, the idea of a triumphant return no longer sounded so fanciful.

• D'Angelo plays the O2 Academy in Brixton, London on Friday 3 February and Saturday 4 February 2012